1. Field of the Disclosure
The disclosure relates generally to inventory management, and in particular, to managing inventory using active RFID technologies.
2. The Prior Art
Background
Accurately tracking inventory is crucial for manufacturing companies. When companies cannot properly track inventory, improper stock balances may lead to increased financial costs and customer dissatisfaction. One area where inventory management is problematic is when inventories are dispersed over a wide geographical area, and throughout many different segments of a company. For example, field sales personnel may carry finished goods as samples. A further challenge exists when companies store finished goods at a customer's location on a consignment basis, and the inventory is managed by the customer.
A lack of inventory control can lead to many problems, including the over-stocking of raw materials and finished goods to compensate for poor systems as managers attempt to prevent shortages. Sales and service personnel may also engage in self-serving efforts by stockpiling inventory to get around poor inventory systems. Also, unpredictable inventory levels inevitably lead to increased costs resulting from crisis management when inventory must be expedited as managers attempt to get the right inventory to the customer on time.
Accurate tracking of specific pieces of inventory can become critical when the inventory is a high-value item, such as in the medical and instrumentation industries. Hospitals may store items that cost several thousands of dollars on site in case of a medical emergency. When such an item is consumed, either the hospital must inform the vendor, or a local sales representative will note the use when conducting an on-site visit. Furthermore, field-based personnel often carry around high cost items as samples or service replacements. As a result, inventory managers may not have an accurate account of where high-value assets are located, how many are at a particular location or with a particular employee, or when they are consumed by a customer.
Prior art methods for managing inventory typically comprise bar code scanner-based systems where inventory is tracked by scanning a barcode as the inventory moves from one station to the next. However, scanner-based systems have serious shortcomings when inventory moves out of the immediate factory environment. Sales and service personnel, particularly those that work in the field or at a customer's location, may not be properly trained or otherwise motivated to systematically scan inventory in their possession. Therefore, managers responsible for the company's assets may not have an accurate real-time picture of where their inventory is located.
A newer technology being used in inventory management is Radio Frequency Identification (RFID) that comprises a radio tag that is automatically scanned as it passes near a reader. Passive RFID tags can be effective in a managed factory environment where inventory travels along predetermined routes and resides in known locations. However, passive RFID tags have a range of only several feet, making passive RFID tags only as effective as barcodes when the inventory leaves the factory as the RFID tags must be manually scanned.
Furthermore, passive RFID tags typically do not perform accurately in challenging situations, such as in arbitrary architectural environments where metal structures may be present including metal shelving in a store room, or in the garage of an office building or home. Finally, in the systems of the prior art, inventory enclosed in a metal container, such as the samples contained in the trunk of an employee's car, must be accounted for by hand.